CAMDEN, N.J. - The six men caught up in an alleged plot to attack Fort Dix, the Army base in South Jersey, were arraigned Thursday in federal court in Camden.

All six pleaded not guilty, The New York Times reported. The defendants are all being held without bail.

At another hearing, federal prosecutors told a judge that more than 100 recordings of conversations among the defendants were recorded. They would not say whether the recordings were from wiretapped conversations.

Five of the defendants -- Mohamed Ibrahim Shnewer of Cherry Hill, N.J.; Serdar Tatar of Philadelphia; and Eljvir, Shain and Dritan Duka of Cherry Hill -- face charges including conspiring to kill members of the U.S. military. The three Duka brothers, who were allegedly living in the United States illegally, have also been charged with possession of weapons by a non-citizen.

Agron Abdullahu of Buena Vista Township near Atlantic City is charged with supplying weapons to the Duka brothers.

The investigation began with a tip from a video store clerk who turned over a videotape showing men apparently engaged in weapons practice.